[Spectro-analysis of gas breakdown in laser-induced plasma during laser ablating metal]

We obtained laser-induced plasma by laser ablating aluminium with an Nd:YAG laser, using time- and space-resolved spectroscopy, the effects of ambient gas breakdown on the emission characteristics of laser-induced plasma were studied. Argon, air, nitrogen were used as surrounding atmospheres. The experimental results showed that at the early stage of the plasma, there were many Ar+ lines in the plasma produced in argon; O+, N+ in the plasma produced in air; and N+ in the plasma produced in N2. Based on the time- and space-resolved emission spectra of the plasma at different laser beam energy, gas breakdown phenomena were analyzed when the aluminium was ablazed by laser. The effects of gas breakdown were briefly discussed.